Polymer compounds with 2-(1-aziridinyl) alkyl acrylates and methacrylates



United States Patent 3,480,601 POLYMER COMPOUNDS WITH Z-(I-AZIRIDINYL)ALKYL ACRYLATES AND METHACRYLATES Theodore L. Ashby and Donald B.Parrish, Lake Jackson,

Tex., assignors to The Dow Chemical Company, Midland, Mich., acorporation of Delaware No Drawing. Continuation-impart of applicationSer. No. 468,576, June 30, 1965. This application Oct. 30, 1967, Ser.No. 679,232

Int. Cl. C08f /00 U.S. Cl. 26086.1 11 Claims ABSTRACT OF THE DISCLOSURECopolymers useful as protective coatings, sizes for paper and textiles,and the like are prepared by copolymerlzlng 2-(l-aziridinyl) alkylacrylates or methacrylates,

This is a continuation-in-part of our copending application Ser. No.468,576 filed on June 30, 1965 and now abandoned.

This invention relates to new compositions of matter containing2-(1-aziridinyl) alkyl acrylates and methacrylates. More particularly itrelates to polymer compositions comprising 2-(1-aziridinyl) alkylacrylates or methacrylates and other ethylenically unsaturated organiccompounds copolymerizable therewith and to a method of making same.

The present invention is accomplished in a polymeric compositioncomprising 1) from about A percent to about 50 percent by weight basedon the weight of the polymer of an acrylic ester selected from the groupconsisting of a 2-(l-aziridinyl) alkyl acrylate and a 2-(1- aziridinyl)alkyl methacrylate, and (2) from about 99% percent to about 50 percentby weight based on the weight of the polymer of at least one otherethylenically unsaturated comonomer copolymerizable therewith.

The 2-(1-aziridinyl) alkyl acrylates and 2-(l-aziridinyl) alkylmethacrylates employed in the present invention may be represented bythe formula 1120 R O R wherein R is hydrogen, methyl or ethyl and R ishydrogen or methyl.

A compound of the above formula is polymerized with one or moreethylenically unsaturated comonomers usually at elevated temperatures inthe presence of a free radical catalyst. Ethylenically unsaturatedcomonomers copolymerizable with said aziridinyl acrylates ormethacrylates include vinyl aromatic monomers; esters of a,[3-unsaturated acids and in particular esters of acrylic and methacrylicacid; acrylamide or methacrylamide; acrylonitrile; dienes; vinylpyrrolidone and N-vinyl morpholine, and the like.

Suitable aromatic monomers include styrene, vinyl toluene, u-methylstyrene, the various halogenated styrenes such as p-chlorostyrene or2,5-dibromostyrene, alkylated styrenes such as t-butyl styrene, vinylnaphthalene, 1,1-diphenylethylene and the like. Suitable esters includethose having the formula of methyl. Suitable dienes include butadiene,isoprene, 2-halo-1,3-butadiene wherein halo is bromine or chlorine.

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Copolymerizability of a monomer is readily determined by well knownexperimental methods or techniques. Mon omers having a group which isreactive with the aziridinyl group during polymerization, such asacrylic acid or methacrylic acid, are included among those monomers notcopolymerizable with said aziridinyl alkyl acrylates or methacrylates.

The polymers of the present invention are accomplished by reactingtogether in an inert liquid hydrocarbon solvent, (1) a 2-(1-aziridinyl)alkyl acrylate or a 2-(1- aziridinyl) alkyl methacrylate and (2) atleast one other ethylenically unsaturated comonomer in the presence of afree radical catalyst.

Elevated tempeartures are employed during the course of the reaction inorder to decrease the reaction time. Temperatures of from about 40 C. toabout 150 C. and preferably from about 60 C. to about 110 C. areemployed during the reaction.

Catalysts employed in the invention are free radical catalysts. Theparticular free radical catalyst employed is not critical and thoseknown to the art are acceptable. Examples of such catalysts includeperoxy compounds such as lauroyl peroxide, benzoyl peroxides; azocompounds such as azobisisobutyronitrile and per salt compounds such astributyl perbenzoate. It is to be understood that radiation from a radioactive source, such as a cobalt-60 source may also be employed.

The polymerization reaction is preferably carried out in an inert liquidorganic solvent. The amount of solvent is not critical to the reactionbut a large excess is not desirable. Examples of inert solvents whichmay be employed in the reaction include toluene, xylene, methyl ethylketone, dimethyl formamide and the like.

The polymerization may be carried out by any of the known methods in theart such as solution polymerization and bulk polymerization. In bulkpolymerization, the reactants are subjected to polymerizable conditionswithout the presence of a solvent. The preferred. method is to employsolution polymerization since the monomers are dis solved in a suitablesolvent and in this particular type of polymerization, the uppertemperature limit of the system depends upon the boiling point of thesolvent and/ or monomers.

It is to be understood that the polymerization reaction is not limitedto one of the aziridinyl compounds and one of the copolymerizablemonomers but that two or more of the aziridinyl compounds may bepolymerized with one or more of the hereinbefore mentionedcopolymerizable monomers. It is preferred, however, that either a2-(1-aziridinyl) alkyl acrylate or a 2-(l-aziridinyl) alkyl methacrylatebe polymerized with one or two of the copolymerizable monomers toproduce copolymers or terpolymers of the invention.

In the polymerization reaction, from about percent to about 50 percentby weight of the aziridinyl compound is polymerized with from about 99%percent to about 50 percent by weight of the copolymerizable monomer atelevated temperatures, the percent by Weight being based on the totalweight of the monomer mixture.

The polymers of the present invention may be used as sizing for paperand textiles, protective coatings, encapsulating, moldings, and thelike. The polymers, even those polymers containing low levels ofaziridinyl ester, show greatly improved adhesion to a variety ofsubstrata.

The following examples are illustrative of the invention and are notintended to limit the: scope thereof.

Example 1.10 percent aziridine compound, percent styrene Into a reactionvessel equipped with means for stirring, temperature control, refluxing,nitrogen purging, and reactant addition were placed 2,000 g. of toluene.The

Solids percent 52.3 Conversion based on V.P.C. do 99 Viscosity,centistokes (cs.) 1.02 No. avg. mol. wt. 40,000

1 Vapor phase chromatography In this example and the following 5examples, the vlscosity was determined as a 1 percent solution of thereaction product in toluene at 100 F. in a conventional OstwaldViscometer.

Example 2. percent aziridine compound, 85 percent tyrene Into a reactionvessel as described in Example 1 were placed 2,000 g. of toluene and thetemperature raised to 110 C. While maintaining this temperature, amonomers-catalyst mixture was added dropwise over a 4 /2 hour period.This mixture consisted of 1,700 g. of styrene, 300 g. of2-(l-aziridinyl) ethyl methacrylate and g. of di-t-butyl peroxide.During the addition, the temperature was maintained at 110 C. and uponcompleting the addition, the reaction mixture was digested for about 31/2 hours at 110 C. The resulting product was a clear,

pale yellow viscous liquid observed to have the following:

Solids percent 51.8 Conversion do 99 Viscosity (cs.) 0.82 No. avg. mol.wt. 30,500 Gardner color 16 Example 3.20 percent aziridine compound, 80percent styrene Into a reaction vessel as described in Example 1 Wereplaced 2,000 g. of toluene and the temperature raised to 110 C. Whilemaintaining this temperature, a monomers-catalyst mixture was addeddropwise over a 79 minute period. The mixture consisted of 1,600 g. ofstyrene, 400 g. of 2-(1-aziridinyl) ethyl methacrylate, and 20 g. ofdi-t-butyl peroxide. During the addition of the above mixture, thetemperature was maintained at 110 C. and upon completing the addition,the reaction mixture was digested for about 45 hours at 110 C. Theresulting product was a colorless viscous liquid observed to have thefollowing:

Solids percent 50.8 Conversion do 99 Viscosity, (cs.) 0.89 No. avg. mol.wt. 38,000 Gardner color 1 Example 4.- percent aziridine compound, 75percent styrene product was a clear yellow viscous liquid observed tohave the following:

Solids percent 51.1 Conversion do 98 Viscosity (cs.) 0.91 No. avg. mol.wt. 40,000 Gardner color 1 Example 5.20 percent aziridine compound,percent cyclohexyl acrylate Into a reaction vessel as described inExample 1 were placed 1,000 g. of toluene and the temperature raised to110 C. While maintaining this temperature, a monomers-catalyst mixturewas added dropwise over about a 2 hour period. The mixture consisted of800 g. of cyclohexyl acrylate, 200 g. of 2-(1-aziridinyl) ethylmethacrylate, and 10 g. of di-t-butyl peroxide. During the addition ofthe above mixture, the temperature was maintained at 110 C. and uponcompleting the addition, the reaction mixture was digested for about 25/2 hours at C. The resulting product was a yellow, clear, liquid lessviscous than the previous products and observed to have the following:

Solids percent 50.2 Conversion do 99 Viscosity (cs.) 0.83 No. avg. mol.wt. 13,500 Gardner color 1 Example 6.20 percent aziridine compound, 80percent methyl methacrylate Into a reaction vessel as described inExample 1 were placed 1,976 g. of toluene and the temperature raised toC. While maintaining this temperature, a monomerscatalyst mixture wasadded dropwise over about a 2 /2 hour period. The mixture consisted of790 g. of methyl methacrylate, 198 g. of 2-(1-aziridinyl) ethylmethacrylate, and 9.9 g. of di-t-butyl peroxide. Upon completion of theaddition of the monomers-catalyst mixture, the temperature was loweredto and maintained at a temperature of 99 C. for about 51 hours. Theresulting product was a clear, colorless, viscous liquid observed tohave the following:

Solids percent 35.1 Conversion do 99 Viscosity (cs.) 0.91 No. avg. mol.wt. 40,000 Gardner color 1 Example 7.20 percent aziridine compound, 40percent methyl methacrylate, 40 percent butyl acrylate Into a reactionvessel as described in Example 1 were placed 2,000 g. of xylene and thetemperature raised to 98 C. While maintaining this temperature, amonomerscatalyst mixture was added dropwise over a 4 hour period. Themixture consisted of 800 g. of methyl methacrylate, 800 g. of butylacrylate, 400 g. of 2-(1-aziridinyl) ethyl methacrylate and 20 g. ofdi-t-butyl perbenzoate. Upon completion of the above monomers-catalystaddition, the reaction mixture was digested for 25 hours at 98 C. Theresulting product was a clear, pale yellow, viscous liquid observed tohave the following:

Solids percent 50.4 Conversion do 99 Viscosity (cs.) 0.85 No. avg. mol.wt. 8,700 Gardner color 1 The viscosity was determined as a 1 percentsolution of the reaction product in xylene at 100 F. in a conventionalOstwald Viscometer.

A portion of the polymer product of each of Examples 1 through 7 wastested for stability. The polymer was placed in a closed container andperiodically a small portion of the polymer was titrated to determinethe concentration of aziridine remaining in the product. A pyridine-H01titration method was employed. The tests showed that all the polymershad a shelf life or stability of greater than eight months.

Example 8 A citrate bottle was loaded with 50 g. of toluene, g. of butylacrylate, 70 g. of methyl methacrylate, 20 g. of 2-(1-aziridinyl) ethylmethacrylate and 1 g. of azobisisobutyronitrile. The bottle was cappedwith a conventional crown capping machine and placed into an oil bath at60 C. for 24 hours. The resulting product was a clear viscous liquidhaving 64.9 percent solids and 98 percent conversion to the resultingpolymer.

Example 9 Into a reaction vessel, equipped with means for stirring,temperature control, refluxing and monomer addition, were placed 150 g.of toluene, 105 g. of styrene, g. of butyl acrylate, 30 g. of2-(1-aziridinyl) ethyl methacrylate and 0.75 g. ofazobisisobutyronitiile. The temperature on this charge was maintained atabout 80 C. for 24 hours. The resulting product was a clear viscousliquid having 19 percent solids and 39 percent conversion to theresulting polymer.

Example 10 The procedure of Example 9 was substantially repeated exceptthat the following reactants were substituted:

G. Xylene 200 Butyl acrylate Methyl methacrylate 140 2-(1-aziridinyl)ethyl methacrylate 40 Azobisisobutyronitrile 2 The reaction was carriedout at 70 C. for a period of 24 hours. The reaction product was a clearviscous liquid having 50 percent solids and 100 percent conversion tothe resulting polymer.

Example 11 The procedure of Example 8 was substantially repeated exceptthat the following reactants were substituted:

Xylene 100 2-(l-aziridinyl)ethyl methacrylate 20 Azobisisobutyronitrilel Styrene 80 The reaction was carried out at 70 C. for a period of 24hours. The reaction product was a clear viscous liquid having 35 percentsolids and 69 percent conversion to the resulting polymer.

Example 12 The procedure of Example 9 was substantially repeated exceptthat the following reactants were substituted:

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G. Pentoxone 200 Styrene 160 2-(l-aziridinyl)ethyl methacrylate 40Di-t-butyl peroxide 2 Pentoxone is H (CH);-C-CHz-C-OHa(4-methoxy4-rnethylpentan0ne-2) The reaction was carriedout at 110 C. for a period of 24 hours. The reaction product was a clearviscous liquid having 49 percent solids and 97 percent conversion to theresulting polymer.

Example 13 The procedure of Example 9 was substantially repeated exceptthat the following reactants were substituted:

G. Xylene 200 Styrene 2-(1-aziridinyl)ethyl methacrylate 40 Benzoylperoxide 1.5

Di-t-butyl peroxide 2 The reaction was carried out at a temperature of120 C. for a period of 16 hours. The reaction product was a clearviscous liquid having 46 percent solids and 95.8 percent conversion tothe resulting polymer.

Example 14 The procedure of Example 9 was substantially repeated exceptthat the following reactants were substituted:

G. Propylene glycol methylether 400 Styrene 340 2-(1-aziridinyl)ethylmethacrylate 60 Benzoyl peroxide 6 Di-t-butyl peroxide 2 Tre reactionwas carried out at a temperature of 60 C. for a period of 16 hours. Thereaction product was a clear viscous liquid having 37.7 percent solidsand a conversion of 75 percent to the resulting polymer.

Example 15 The procedure of Example 9 was substantially repeated exceptthat the following reactants were substituted:

G. Xylene 375 Styrene 262.5 2-(1-aziridinyl)ethyl methacrylate 113.5Azobisisobutyronitrile 3.8

The reaction was carried out at a temperature of 110 C. for a period of16 hours. The reaction product was a clear viscous liquid having 39percent solids.

Example 16 The procedure of Example 8 was substantially repeated exceptthat the following reactants were substituted:

G. Isopropanol 79 Isobutyl acrylate 25 2(l-aziridinyl)ethyl methacrylate25 Azobisisobutyronitrile 0.5

The reaction was carried out at a temperature of 60 C. for a period of17 hours. The reaction product was a clear viscous liquid having39percent solids.

Example 17 In a manner similar to the preceding examples the followingmonomers were polymerized:

Grn. Methyl methacrylate Butyl acrylate 105 3 gm. 2-(1-aziridinyl)ethy1methacrylate using 3 grns of 2,2'-azobisisobutyronitrile as the catalystand ethyl acetate (150 gm.) and benzene (150 gm.) as the solvent. Thepolymerization was carried out at a temperature of 75 C. during theaddition of monomers and raised to 80 C. thereafter. The polymersolution was clear with a slight yellow tint, had a solids content of51.8% and a Gardner viscosity of Y/Z.

Example 19 Likewise, a copolymer was prepared from 60 parts of2-(l-aziridinyl) ethyl methacrylate and 240 parts of acrylonitrile in700 parts of dimethyl formamide as the solvent using 3.5 parts ofcatalyst. Polymerization was carried out for 22 hours.

The final polymer solution contained 28.3 weight percent non-volatilesolids, had a Gardner color of 17.5, had a Brookfield viscosity of 54cps. at 25 C. and a predominant molecular weight of about 30,000 asdetermined by gel permeation chromatography.

Example Similar to Example 19, a copolymer was prepared by replacing theacrylonitrile with o-chlorostyrene and the formamide solvent withtoluene. The resultant polymer solution had a Gardner color of less than1 and a Brookfield viscosity of 12 cps. at C. The predominant molecularweight of the copolymer was about 20,000.

What is claimed is:

1. A free radical polymerized copolymer comprising (a) from about A toabout percent by weight of a 2-(1-aziridinyl)alkyl acrylate ormethacrylate monomer having the formula:

wherein R is hydrogen, methyl or ethyl and R is hydrogen or methyl and(b) from about 99% to about 50 percent by weight of at least one otherethylenically unsaturated monomer copolymerizable therewith selectedfrom the group consisting of vinyl aromatic monomers, esters ofa,;3-unsaturated acids, acrylamide, methacrylamide, acrylonitrile,conjugated aliphatic dienes, vinyl pyrrolidone and N-vinyl morpholine.

2. The composition of claim 1 wherein said vinyl aromatic monomer isstyrene or o-chlorostyrene.

3. The copolymer of claim 1 wherein the aziridinyl methacrylate is2-(1-aziridinyl) ethyl methacrylate.

4. The copolymer of claim 1 wherein the copolymerizable monomer is anester of an unsaturated acid having the formula CHFC-C-OR wherein R ishydrogen or methyl and R is a monovalent hydrocarbon radical containingfrom 1 to about 12 carbon atoms.

5. The copolymer of claim 4 wherein said hydrocarbon radical iscyclohexyl, methyl, butyl or isobutyl.

6. A copolymer comprising essentially the composition of claim 1dissolved in an inert organic solvent.

7. A process for producing novel copolymers which comprises polymerizingin the presence of free radicals at temperatures of about 40 C. to aboutC. in an inert solvent (a) from about A to about 50 percent by weight ofa 2-(1-aziridinyl)alkyl acrylate or methacrylate monomer having theformula:

1120 R O R wherein R is hydrogen, methyl or ethyl and R is hydrogen ormethyl and (b) from about 99% to about 50 percent by weight of at leastone other ethylenically unsaturated monomer copolymerizable therewithselected from the group consisting of vinyl aromatic monomers, esters ofa,,8-unsaturated acids, acrylamide, methacrylamide, acrylonitrile,conjugated aliphatic dienes, vinyl pyrrolidone and N-vinyl morpholine.

8. The process of claim 7 wherein the aziridinyl methacrylate is2-(1-aziridinyl) ethyl methacrylate.

9. The process of claim 7 wherein the copolymerizable monomer is anester of an unsaturated acid having the formula R o OIIz C-ii-OR whereinR is hydrogen or methyl and R is a monovalent hydrocarbon radicalcontaining from 1 to about 12 carbon atoms.

10. The process of claim 9 wherein said hydrocarbon radical iscycloheXyl, methyl, butyl or isobutyl.

11. The process of claim 7 wherein said aromatic monomer is styrene oro-chlorostyrene.

References Cited UNITED STATES PATENTS 2,654,737 10/1953 Bestian et al.260-883 3,006,912 10/1961 Vierling et a1. 260-883 3,017,280 1/1962Yudelson. 3,290,416 12/1966 Christenson et al. 3,383,373 5/1968 Waples260-867 HARRY WONG, 111., Primary Examiner US. Cl. X.R.

